Parking a vehicle in tight spaces is a challenging task to perform due to the scarcity of feasible paths that are also collision-free. This paper presents a strategy to tackle this kind of maneuver with a modified Hybrid-A* path-planning algorithm that combines the feasibility guarantee inherent in the standard Hybrid A* algorithm with the addition of static obstacle collision avoidance. A kinematic single-track model is derived to describe the low-speed motion of the vehicle, which is subsequently used as the motion model in the Hybrid A* path-planning algorithm to generate feasible motion primitive branches. The model states are also used to reconstruct the vehicle centerline, which, in conjunction with an inflated binary occupancy map, facilitates static obstacle collision avoidance functions. Simulation study and animation are set up to test the efficacy of the approach, and the proposed algorithm proves to consistently provide kinematically feasible trajectories that are also collision-free.

翻译：在狭窄空间内泊车是一项具有挑战性的任务，因为既可行又无碰撞的路径十分稀缺。本文提出一种应对此类操作的策略，采用改进的混合A*路径规划算法，该算法在标准混合A*算法固有的可行性保证基础上，增加了静态障碍物碰撞避免功能。通过推导运动学单轨模型来描述车辆的低速运动，该模型随后被用作混合A*路径规划算法中的运动模型，以生成可行的运动基元分支。模型状态还用于重构车辆中心线，结合膨胀的二值占据栅格图，实现了静态障碍物碰撞避免功能。通过搭建仿真研究和动画验证该方法的有效性，所提算法被证明能持续提供运动学可行且无碰撞的轨迹。